Summarizing a decade of research at the University of California, this paper concludes that admissions criteria that tap student mastery of curriculum content, such as high-school grades and performance on achievement tests, are stronger predictors of success in college and are fairer to poor and minority applicants than tests of general reasoning such as the SAT. [Paper prepared for inaugural conference of Center for Enrollment Research, Policy and Practice: "Defining Enrollment in the 21st Century: Understanding Our Students and Our Commitments," University of Southern California, August 4-6, 2008.]